to be honest i am a bit lost with all the Information provied here. I have the feeling that the Infos i need are present in some Threads, but either i overread it, just used the wrong keywords for my search (as i dont even know what it is called what i am searching for) or i just dont get it .
I ask you for your understanding and patient.

Maybe this Summary of questions can be usefull for any other who is searching for a similar solution.

I have an UE46F5370 TV with installed Firmware 2126 and an external 1TB HDD-Drive with recorded Files (which got encrypted since i fool started a Firmware Update some time ago). I already copied the encrypted Files via Linux also on my internal HDD-Drive. TV is in local Network. I don't need a permanent working Solution for using PVR of my TV in future, i just want to decrypt the already existing Files. Also i don't want to root my TV.

I tried the Programm from the latter Thread (drmdecrypt), resulting in a non readable *.ts file.
So before doing any further Research or Attempts i would like to ask you experts, now knowing my preconditions, a few basic questions regarding decryption of the files - To have a solid basis to continue research or to abandon hope .

Is it even possible to encrypt any sort of decrypted *.srf Files (directly on TV, on my local Linux/Windows Machine, via Network... etc.) without rooting my TV ?

If yes (out of interest): Is the rooting neccessary to extract the used Key for the encrypted Files?

If yes (out of interest): Would it even be possible to decrypt Files that have been encrypted before rooting the TV or is it just working with root-recorded Files?

If no: Any kind of hint to a Thread or Programm that will do the job is much appreciated.

Is it possible to downgrade to an older TV Firmware-Version? (i guess not, since decryption will not work if Key missing internaly in TV). Maybe it's possible to downgrade to any specific Version with a weaker encryption?

Alternatively I thought about any kind of streaming or accessing the HDD over Network via the TV or directly via some kind of TV-Output to let the TV decrypt the Files while my PC is recording the Stream, is this possible in any way?